Code the following functions in a single lisp file named homework.lisp. 1. add (number number) Write a function named add that takes two numbers as parameters and returns the sum of the two numbers 2. minimum (list) Write a function named minimum that takes a list of numbers as a parameter. Search the entire list and return the smallest value from the list. 3. average (list) Write a function named average that takes a list of numbers as a parameter. Return the average of all numbers in the list 4. count-of (symbol list) Write a function named count-of that takes two parameters, a symbol and a list. Count the number of instances of x in the list. Do not count the number of x in any sub-lists within the list